Continuing the Garden Indoors
Stephanie Duer
Novermber 22, 2006
It finally feels that winter is nearing; there is snow on the mountains, we’ve stopped mowing our lawns, and have put the tools and barbeque away. The glorious colors of the autumn garden are gone and its time to put it all to rest. Then again, for those of us who just can’t stop gardening, the bounty of bulbs available for fall planting also provide an opportunity for brightening the winter months with gorgeous blooms indoors.
Forcing bulbs indoors is an opportunity to have glorious spring blooming flowers all winter long. The term forcing refers to inducing a plant to produce its shoot, leaf, and flower ahead of its natural blooming season and outside of its environment. To force bulbs, you need to mimic and compress the natural process that would occur in the garden. For some bulbs, this means providing a period of chilling and darkness, but with some bulbs, it’s as simple as sitting them in water and providing an abundance of light.
When selecting bulbs for forcing, it’s important to keep in mind two things: the process needed to force the bloom, and second, the amount of time it will take and these depend on the type of bulb you choose. It’s important to know these things when you start, as you want to be certain that the tulips you’re potting up will be flowering for your big event.
Any bulb can be forced, but some take more work and time than others. For instance, tulips make a lovely holiday display, as do crocus, but both require chilling time. Other bulbs, such as paper whites, only need water and adequate light. Bulb catalogs and stores often offer bulbs specifically for forcing; these are usually bulbs that force easily or are pre-chilled, reducing the time required for forcing.
When selecting bulbs, look for bulbs that are:
- Healthy and plump, not shriveled or dry
- Free of soft spots or mold
- Smell of earth or greenness, but not of rot
After selecting the bulbs, the next step in forcing is to pot the bulbs. Any container will do as long as it has good drainage. I sometimes force bulbs in simple plastic nursery pots and then set them into other containers or displays when they bloom.
To plant bulbs, choose a potting soil that is high in peat. I sometimes mix my own using equal parts shredded peat moss, potting soil, and vermiculite, and I don’t bother adding fertilizer as all the nutrients the bulb needs are contained within the bulb. If you are planting more than one pot, or are planting for a succession of blooms, label the pots with the variety, the planting date, and the anticipated bloom date.
Place a few pieces of broken pottery over the drain holes to keep soil in and let the water out. Fill the pot about three fourths full with soil, and place the bulbs, stem up and root down, on the soil. Pour soil over the bulbs, leaving the tips of the bulbs exposed. When potting tulip bulbs, place them so that the flat side of the bulb faces the container. This will allow the first leaves to form a border around the edge of the pot. Water until water comes out of the drain holes, adding a bit more soil if necessary, and then water again.
You can plant more than one bulb in a pot, and even more than one kind of bulb. Be sure to choose flowers with similar blooming periods to maximize the show, and minimize the chance of having pots with half-spent flowers.
Once potted, the bulbs need to be chilled in order to mimic the conditions in which they grow. Bulbs need to be placed in a dark location with temperatures between 38 and 50 degrees. Cool cellars, unheated garages, or the crisper portion of a refrigerator are ideal locations. To ensure darkness, place a paper bag over the pot. Keep bulbs away from fruits during this period, as some fruits emit gasses that inhibit a bulbs ability to bloom.
Check the pots periodically, and water while the soil is still just damp. Do not allow the soil to dry out. Roots will begin to appear in smaller containers within five to six weeks, but forcing takes time. Early blooming bulbs such as snowdrops, crocus, or daffodil, require about twelve weeks, tulips about sixteen weeks. A good rule of thumb is that when shoots are two to three inches above the soil, it’s time to bring the pots out of storage. At this stage, move the pots into a cool location, such as an entry way or unheated bedroom, where they receive only indirect light, and don’t forget to water them.
When the foliage and flower buds are well developed, move the pot into a bright, sunny spot. Once the flowers open, move the pot out of the direct light to prolong the blooms.
Paper whites are the simplest bulb to force as they require no chilling period. Simply select a pot (one without drainage is fine) and fill with clean gravel. Place the bulbs on the gravel, snugging them down just a bit, and pour water into the container to just below the top of the gravel. Keep them in a cool, bright place and maintain the water level to just the bottom of the bulb. In three to five weeks you’ll have beautiful, fragrant paper whites.
When the bulbs are finished blooming, they can be saved to be planted in the garden. However, forcing exhausts bulbs and they sometimes will not re-bloom. I add mine to the compost pile which in time will feed the soil and the bulbs planted outside awaiting spring.
Forcing bulbs to bloom indoors brightens long and dark winter days and makes it seem that spring isn’t so far away. And for those of us who just can’t get enough of the garden, it bridges that long span between putting the fall garden to bed and the arrival of those spring catalogs!